Precipitation Rate and Particle Size Distribution of Seeded Precipitation Process in Sodium and Potassium Aluminate Solutions

Abstract

The pptn. rate and particle size distribution(PSD) for pure sodium aluminate soln. and potassium aluminate solns. were investigated. The XRD, SEM and TG/DTG curves were used to study the products of sodium aluminate soln. and potassium aluminate soln. The results show that the pptn. rate of potassium aluminate soln. is larger than that of sodium aluminate soln., and the rate increases with the decrease of original ak of caustic aluminate soln. under the same conditions. There are dramatic discrepancies of PSD during the same seeded pptn. condition between sodium aluminate soln. and potassium aluminate soln. The XRD patterns of products show that the crystals of potassium aluminate soln. have better crystallinity than that of sodium aluminate soln., but the TG/DTG curves of products of sodium aluminate soln. and potassium aluminate soln. have no obvious difference. These discrepancies are similar in solns. of different ak(1.45, 1.55, 1.65). It is considered that the difference of nucleation rate between sodium aluminate soln. and potassium aluminate soln. is the reason for the discrepancy of pptn. rate and PSD during seeded pptn. Particle size distribution Precipitation (chemical) (pptn. rate and particle size distribution in seeded pptn. process of sodium aluminate and potassium aluminate solns.)